Exercise stress test
An exercise stress test is a screening tool to test the effect of exercise on your heart.
How the Test is Performed
You will walk on a treadmill while the electrical activity of your heart is measured with an electrocardiogram (ECG), and blood pressure readings are taken. This will measure your heart's reaction to your body's increased need for oxygen.
Bruce Protocol is the commonest protocol followed.It consists of 7 stages.Every stage is three minutes each.Stating speed is 1.7(mph) and gradient is 10%.Steady increment of 0.7-0.8(mph)speed and 2% in gradient is given.
Modified Bruce Protocol is another protocol widely used.It starts with speed 1.7(mph) and gradient 0%.
Stage 2 and 3 Speed remains same but gradient increses by 5%.Subsequent stages are similar as the Bruce Protocol.Used in patients in poor condition clinically.
The test continues until:
- You reach a target heart rate
- You develop complications such as chest pain or an exaggerated rise or drop in blood pressure
- ECG changes show that your heart muscle is not getting enough oxygen
How to Prepare for the Test
- You must not eat, smoke, or drink beverages containing caffeine or alcohol for 3 hours (or more) before the test.
- You should continue all medications unless instructed otherwise (several types of medications are often avoided before an exercise stress test).
- Wear comfortable shoes and loose clothing to allow you to exercise.
How the Test Will Feel
Electrodes (conductive patches) will be placed on your chest to record the heart's activity. The preparation of the electrode sites on your chest may produce a mild burning or stinging sensation.
The blood pressure cuff on your arm will be inflated every few minutes, producing a squeezing sensation that may feel tight. Baseline measurements of heart rate and blood pressure will be taken before exercise starts.
You will start walking on a treadmill or pedaling a stationary bicycle. The pace and incline of the treadmill (or the pedaling resistance) will gradually be increased.
Rarely, people experience the following during the test:
- Chest discomfort
- Shortness of breath
Why the Test is Performed
An exercise test is most often done to evaluate for coronary artery disease.
Reasons why an exercise stress test may be performed include:
- You are having chest pain (to evaluate for coronary artery disease -- narrowing of the arteries that feed the heart muscle)
- Your angina is becoming more severe or is occurring more often
- You have had a heart attack
- You have had angioplasty or heart bypass surgery
- You are going to start an exercise program and you have heart disease or certain risk factors, such as diabetes
- To identify heart rhythm changes that may occur during exercise
- To evaluate the significance of a heart valve program (such as aortic valve stenosis or mitral valve stenosis)
Normally, heart rate increases in proportion to the workload. Your endurance levels should be appropriate for your age and conditioning level.
What Abnormal Results Mean
Abnormal results may indicate:
- Arrhythmias during exercise
- Lack of aerobic fitness
- Possible coronary artery disease (blockage in the arteries)
- Stress on the heart triggered by exercise
Stress tests are generally safe. Some patients may have chest pain or may faint or collapse. A heart attack or dangerous irregular rhythm is rare.
Persons who are likely to have such complications are usually already known to have weak hearts, so they are not given this test.
A stress test is less accurate in young or middle-aged women with symptoms that are not typical of heart disease.
Please note that a defibrillator and qualified personal and equipments for resuscitation should be on standby during the test.